Campus QoS Design

haitham.jneid · ‎08-15-2016

Hi Experts,

I need support on designing and configuring QoS for a campus network which consists of 3 layers:

Access Layer (Cisco 3850)
Distribution Layer (Cisco 6800)
Core Layer (Cisco ASR920)

Attached is the network topology for the campus.

we have Cisco IP phones attached to Cisco 3850 and PCs attached to IP phones.

I need a sample QoS configuration on each node on how to prioritize voice/data traffic from access to distribution to core and vice versa.

Appreciate your valuable support.

thanks,

Haitham Jneid

Francesco Molino · ‎08-15-2016

Hi

First of all I'll paste right here some docs that would be helpful:

1. For Catalyst 3850 and 6800: http://d2zmdbbm9feqrf.cloudfront.net/2016/eur/pdf/BRKCRS-2501.pdf

2. For ASR 920:

- http://www.cisco.com/c/en/us/td/docs/routers/asr920/configuration/guide/qos/qos-plcshp-xe-3-13s-asr920-book/qos-plcshp-class-plc.html

- http://www.cisco.com/c/en/us/td/docs/routers/asr920/configuration/guide/qos/qos-mqc-xe-3-13s-asr920-book.html

- http://www.cisco.com/c/en/us/td/docs/routers/asr920/configuration/guide/qos-classn/qos-classn-xe-3-13s-asr920-book/qos-classn-xe-3s-asr903-book_chapter_01.html

The goal is to mark and classify traffic on your Catalyst 3850. For IP Phone, as they're marking their DSCP, you can just trust the DSCP received. For Catalyst 6800 and ASR, without doing anything, you have your DSCP trusted.

Then the 2nd thing would be on Catalyst 3850 and 6800, to create a policy-map and prioritize the voice traffic compared to data where you'll just specify a bandwidth to be used.

On ASR, as it's your core switch going to outside, you can add in addition of prioritize, the utilization of a maximum specific bandwidth.

I'll not write down all config as you have all written on document pasted before.

Hope that could helps.

Thanks

PS: Please don't forget to rate and mark as correct answer if this answered your question

Thanks
Francesco
PS: Please don't forget to rate and select as validated answer if this answered your question

haitham.jneid · ‎08-15-2016

Hi,

I really appreciate your kind support.

one more thing, please correct me if I am wrong.

I will create a policy to classify and mark traffic and apply this policy to the user facing port on the 3850 in the IN direction.

for the uplink from 3850 to 6800, I will create another policy to policy/prioritize/queuing voice/data traffic and apply it on the uplink in the output direction.

on the distribution switch, I will trust the marking coming from 3850 and on the uplink to the core, i will create policy to policy/prioritize/queuing voice/data traffic and apply it in the egress direction

and so on.

is this configuration correct?

and should I do it in the reverse direction from core to access??

thank you.

Haitham Jneid